Leflunomide-Induced Drug Reaction With Eosinophilia and Systemic Symptoms: A Diagnostic Dilemma.

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a severe idiosyncratic drug reaction. This commonly manifests with fever, lymphadenopathy, and a maculopapular rash. It can be fatal if early diagnosis and removal of the offending agent do not occur. Leflunomide, a disease-modifying antirheumatic drug (DMARD) has been rarely associated with DRESS syndrome. Here, we present the case of a 59-year-old male patient admitted with leflunomide-induced DRESS syndrome.